iTunes purchased music (AAC) > MP3 Player

Help me out here guys (and gals). A friend of mine has purchased a bunch of music from the (Windows) iTunes store. He recently bought his wife an MP3 Player; I think it's an iRiver. He wants to get his purchased AAC music to his wife's new player, obviously.

The only way I can think about how to do this is to burn all his purchased music as an MP3 CD and then dump those into the iRiver software. I dunno.